Each train could get speeds of around one gigabit per second (Gbps) which could allow several hundred passengers to stream uninterrupted video content at the same time, the Department for Digital, Culture, Media and Sport (DCMS) said.

Minimum standards for mobile connectivity are being introduced on new franchises but the latest proposals set out plans to improve connectivity for passengers on all mainline routes by 2025.

(Picture: Getty)

Passenger groups said the idea was good but improved connectivity must be delivered faster.

Signal on trains is currently mostly from mobile phone networks operating from remote masts, meaning coverage is patchy and in many places non-existent.

To improve things, the cables and masts would be close to the track in areas where coverage is currently patchy, including in tunnels.

Minister for Digital, Matt Hancock, said: ‘This will not only make journeys more enjoyable and productive, but will help improve the operation and safety of the railway and deliver economic benefits for the whole of the UK.’

Bruce Williamson, of campaign group Railfuture, said: ‘Wi-fi has moved from being an optional extra to something essential for the 21st century rail passenger, so we welcome any improvements to capacity and coverage.

‘Very soon, trains without wi-fi will become unthinkable, and rail passengers will look forward to the day when the phone doesn’t cut out in tunnels.’